Signors to i



Patented May 30, 1933 WALTER BOOK AND EDUARD TSCHUNKUR, OICOLOGNE-MULHEIM, GERMANY, .AS-.

FFICE SIGNORS TO I. G. FARBENINDUSTRIE AKTIENGESELLSCHAFT, OIFRANKFORT-ON- CORPORATION OF GERMANY ARTIFICIAL RUBBER No Drawing.Application filed Iay The present invention relates to the production ofvulcanized artificial rubber goods of especially high quality.

' In accordance with the invention artificial rubber-like masses,obtainable according to various polymerization processes from erythrene,isoprene, monoand dimethylbutadienes and other rubber formingdiolefines, are intimately mixed manner, for instance by rolling,kneading and the like prior to vulcanization, with a most finely dividedsoot variety, such as lamp black and gas black, and then vulcanized inthe customary manner with or without the usual additions, such assulfur, accelerators, etc.

Besides the finely divided other fillers, suchas alkaline-earth oxidesor -carbonates, magnesium oxide, magnesium carbonate, zinc oxide, talcumkaolin, etc. may be applied simultaneously. The quantity of the sootvariety to be added in the most finely divided state varies in very widelimits. It may be mentioned by way of example that generally quantitiesof more than 1%, calculated upon the rubber-like mass employed, willyield good results, but obviously it is also possible to use the fineldivided soot varieties in any quantities wit or without the addition offillers in the normal state of division. Among the artificialrubber-like masses, especially such ones as are obtainable bypolymerizing erythrene, isoprene, or 2.3dimethylbutadiene, for instancein the presence of an alkali metal while heating, will yieldsatisfactory results. Obviously the finely divided soot varieties mayalready be added to the rubber producmg hydrocarbons above mentionedbefore the polymerization of the same, without departing from ourinvention.

on working according to theprocess herein described, artificialrubber-like vulcanizates are obtained of a quality, which so far hasbeen unobtainable in synthetic rubher by any other means and which isproportionately greater than in the case of natural rubber.

Thus, for example, D whose indexof strength soft vulcanizates (that is,the prod-' in any desired soot variety without the addition of 28, 1928,Serial No. 281,587, and in Germany June 10, 1927.

not of the tensile strength in kilograms per square centimeter and ofthe stretch in per cent) amounts to between about 40,000 to about150,000 will easily be obtainable,

whereas in the absence of a finely divided soot variety vulcanizateshaving an index of strength of about 10,000

to 20,000 will be. the normal ones.

Ewample I.20 parts by weight of gas black, 3.15 parts by weight ofsulfur, 9.4 parts by weight of zinc oxide and 1 art by weight ofdiphenylguanidine are roll dd into 78 arts by weight ofdimethylbutadiene rubfibr (methyl rubber) and the mixture is vulcanizedat 143 C. for minutes. The strength of the vulcanization product thusobtained as well as other constants, (the product of the tensilestrength in kilograms per square centimetre and the stretch) are about100% or more higher than in the case of the vulcanization products ofthe same mixture, vulcanized under otherwise identi cal conditions inthe absence of gas black. The durability of the rubber artlcles thusprepared is accordingly very considerably increased.

The proportions of the mixture given in the above example can be variedwithin Wide limits, likewise instead of zinc oxide other additions,increasing elasticity or fillers can be used.

The temperature and duration of the vulcanization can be correspondinglyvaried .within wide limits depending on the characterof thevulcanization accelerator.

Ema/mple .2.100 parts by rene or iso rene are shaken with a solution of4 parts y'weight of egg albumen in 50 parts by weight of water with theaddition of 15 parts by weight of finely divided lamp black at -7 C.until polymerization is complete. The vulcanization products of therubber thus prepared show much higher strength and toughness,

lampblack.

by weight of sulfur, the piperidine salt E wample 5.0.7 parts 0.07 partsby weight of of piperidyldithiocarbamic acld are rolled 100 Thefollowing examples illustrate our -in ,vention without limiting itthereto:

Weight of eryththan those obtained I plastifying media, substances forwhereas when working in the same manner but without the addition of gasblack a vulcanization product is obtained which shows a tensile strengthof about 30-40 kg. per square centimetre at a stretch of about 7 00-1100%.

A vulcanizate of other properties is obtained when using the sameingredients but in another sequence, for instance when roll: ing thesulfur, the accelerator and the gas black .into the erythrenepolymerizate simultaneously, and it is to be understood that in the mostcases the sequence of the addition of the fillers, accelerators etc.changes the properties of the resulting vulcanizates in a certaindegree.

Example 4.0.7 parts by weight of sulfur, 0.07 parts salt ofpiperidyldithiocarbamic acid, 3 parts by weight of most finely dividedmagnesium carbonate and 6 parts by weight of finely divided lamp blackare rolled into 17 parts by weight of erythrene polymerizate (obtainedas described in Example 3) and the mass is vulcanized in a suitablemanner. The quality of the vulcanizate thus obtainable is stillhigherthan those of the vulcanizates described in Example 3.

We claim:

1. As new products soft, rubber-like vulcanizates consisting of avulcanized diole fine p'olymerizate and a finely divided soot variety,said vulcanizates possessing an index of strength between about 40,000and 150,000.

2. As new products soft, rubber-like vulcanizates consisting of avulcanized diolefine polymerizate and gas black, said'vulcanizatespossessing an index'of strength between about 40,000 and 150,000. v

3. As new products soft, rubber-like vulcanizates consisting of avulcanized polymerizate derived from a diolefine hydrocarbon of theformula:

wherein the Xs means hydrogen or methyl, and a finely divided sootvariety, said vulcanizates possessing an index of strength between about40,000 and 150,000.

4. As new products soft, rubber-like vulcanizates consisting of avulcanized polyby weight of the piperidine merizate derived from adiolefine hydrocarbon of the formula:

wherein the Xs mean hydrogen or methyl, and gas black, said vulcanizatespossessing an index of strengthbetween about 40,000 and 150,000. Y

5. As new products soft, rubber-like vulcanizates consisting of avulcanized olymerizate, obtained by polymerizing butadiene in thepresence of an alkali'metal and vulcanizing the polymerizate in thepresence of a finely divided soot variety, said vulcanizates possessingan index-of strength between about 40,000 and 150,000.

6. As new products soft, rubber-like vulcanizates consisting of avulcanized diolefine polymerizate and from about 15% tov about 50% of afinely divided soot variety, based on the amount of the vulcanizate,vulcanizates possessing an index of strength between about 40,000 and150,000.

7 As new products soft, rubber-like vulcanizates consisting ofvulcanized'isoprene polymerizate and a finely divided soot variety, saidvulcanizates possessing an index of strength between about 40,000 and150,000.

8. As new products soft, rubber-like vulcanizates consisting ofvulcanized polymerizate obtained by polymerizing butadiene in thepresence of sodium and vulcanizing 1 the polymerlzate in the presence ofa finely divided soot variet said vulcanizates possessingan index 0strength between about 40,000 and 150,000. 9. As new products soft,rubber-like vulcanizates consisting of vulcanized polymerizates obtainedby polymerizing a diolefine hydrocarbon of the formula:

saidwherein the Xs mean hydrogen or methyl,

in emulsion with water and an emulsifying agent, in the resence of afinely divided soot variety, said vulcanizates possessing an WALTERBOCK. EDUARD TSCHUNKUR.

